Dice tomatoes, tomatillos, and onion. Mince jalapenos (use gloves!). Mix together in a medium bowl.
Squeeze lime juice over prepared mixture. Add vinegar, salt, pepper, and oregano.
Mince cilantro. Add cilantro to taste.
Allow to chill for a few hours before serving. Taste-test before serving and add any salt, pepper, or cilantro as needed.